MustGather information for AIX

The information that is most useful at a point of failure depends, in general, on the type of failure that is experienced.

The IBM® Support Assistant Data Collector is the recommended utility for collecting Java™ diagnostics files for a problem event. The IBM Support Assistant Data Collector collects diagnostic files such as dumps and log files, and helps you to send the information to IBM, if required. For more information, see Using diagnostic tools.

AIX® core file
If the environment is correctly set up to produce full AIX core files (as detailed in Setting up and checking your environment on AIX), a core file is generated when the process receives a terminal signal (that is, SIGSEGV, SIGILL, or SIGABORT). The core file is generated into the current working directory of the process, or at the location pointed to by the label field specified with -Xdump.
For complete analysis of the core file, the IBM support team needs:
  • The core file
  • A copy of the Java executable file that was running the process
  • Copies of all the libraries that were in use when the process core dumped
When a core file is generated:
  1. Run the jextract utility against the core file, see Dump extractor (jextract). Running the jextract utility generates a file called dumpfilename.zip. This compressed file contains the dump and the required Java executable file and libraries.
    Note: The IBM Support Assistant Data Collector runs the jextract utility on system dumps as part of its collection process.
  2. If jextract processing fails, use the snapcore utility to collect the same information. For example, snapcore -d /tmp/savedir core.001 /usr/java8/bin/java creates an archive (snapcore_pid.pax.Z) in the file /tmp/savedir.

You also have the option of looking directly at the core file by using dbx. However, dbx does not have the advantage of understanding Java frames and the JVM control blocks that the Dump Viewer does. Therefore, you are recommended to use the Dump Viewer in preference to dbx.

Java core file:
When a java core file is written, a message (JVMDUMP010I) is written to STDERR telling you the name and full path of the java core file. In addition, a java core file can be actively generated from a running Java process by sending the process a SIGQUIT command. The SIGQUIT command can be initiated by kill -QUIT or Ctrl-\.
JIT dump:
A general protection fault (GPF) or abort event generates a small binary dump of JIT diagnostic data. For more information, see JIT dumps.
The Error Report
The use of errpt -a generates a complete detailed report from the system error log. This report can provide a stack trace, which might not have been generated elsewhere. The report might also point to the source of the problem where it is otherwise ambiguous.